In a liquid crystal display, both surfaces of a liquid crystal cell in which a liquid crystal is retained are generally provided with a polarizer. In order to visually compensate for retardation caused by birefringence of the liquid crystal cell in a front direction and a slanting direction, a birefringent layer is further disposed as an optical compensation layer between the liquid crystal cell and the polarizer. As this birefringent layer, a negative birefringent layer that is obtained by aligning cholesteric liquid crystal molecules on an alignment substrate and whose refractive indices (nx, ny, nz) satisfy a negative uniaxiality “nx=ny>nz” usually is used. The refractive indices (nx, ny, nz) respectively indicate refractive indices in three axial directions in the birefringent layer. The axial directions of the refractive indices (nx, ny, nz) in the birefringent layer are indicated specifically by arrows in a schematic view of FIG. 1. As mentioned above, the refractive indices nx, ny, nz respectively indicate refractive indices in an X-axis direction, a Y-axis direction and a Z-axis direction. As shown in the figure, the X-axis direction is an axial direction exhibiting a maximum refractive index within the plane, the Y-axis direction is an axial direction perpendicular to the X axis within the plane, and the Z-axis direction is a thickness direction perpendicular to the X axis and the Y axis.
As the optical compensation layer, for example, an optical compensation layer is reported, which is provided by forming an alignment film on a support and inclinedly aligning a discotic liquid crystal on this alignment film (see, for example, Patent document 1, and Patent document 2).
It has been also reported that a cholesteric liquid crystal layer is formed by applying a liquid crystal polymer onto an alignment substrate and aligning the liquid crystal polymer, and that the cholesteric liquid crystal layer is used as an optical compensation layer (see Patent document 3, for example).
Patent document 1:Japanese Patent 2692035Patent document 2:Japanese Patent 2802719Patent document 3:Japanese Patent 2660601